Meters and Gauges

System Description

POWER SUPPLY AND GROUND CIRCUIT

Power is supplied at all times
- through 10 A fuse (No.2, located in the fuse block)
- to combination meter terminal 5.

With the ignition switch in the ON or START position, power is supplied
- through 10 A fuse (No.29, located in the fuse block)
- to combination meter terminal 2.

Ground is supplied
- to combination meter terminal 22
- through body ground M51.

WATER TEMPERATURE GAUGE
The water temperature gauge indicates the engine coolant temperature. The reading on the gauge is based on the resistance of the thermal transmitter.
As the temperature of the coolant increases, the resistance of the thermal transmitter decreases. A variable ground is supplied to terminal 25 of the combination meter for the water temperature gauge. The needle on the gauge moves from "C" to "H".

TACHOMETER
The tachometer indicates engine speed in revolutions per minute (rpm).
The tachometer is regulated by a signal
- from terminal 3 of the ECM
- to combination meter terminal 27 for the tachometer.

FUEL GAUGE
The fuel gauge indicates the approximate fuel level in the fuel tank.
The fuel gauge is regulated by a variable ground signal supplied
- from terminal 5 of the fuel level sensor unit
- to combination meter terminal 26 for the fuel gauge
- through terminal 6 of the fuel level sensor unit and
- through body grounds M68, M105 and M130.

SPEEDOMETER
The vehicle speed sensor sends a voltage signal to the combination meter for the speedometer. The voltage is supplied
- to combination meter terminal 11 for the speedometer
- from vehicle speed sensor terminal 1.
The speedometer converts the voltage into the vehicle speed displayed.

MESSAGE CENTER (IF EQUIPPED)
Outside Air Temperature
The message center will display outside air temperature in °C or °F with a range of -40 °C to 60 °C or -40 °F to 140 °F.
An outside air temperature signal is supplied
- to combination meter terminal 24
- from outside air temperature sensor terminal 2.
Ground is supplied to outside air temperature sensor terminal 1 through body grounds E3, E30 and E50.

Average Fuel Economy
Average fuel economy is displayed in liters/100 km or miles/gallon. The vehicle must be moving for average fuel economy to be displayed. If the vehicle is not moving, the display will show "99 L/100 km" or "0 miles/gal". The unified meter control unit calculates average fuel economy based on vehicle speed (signal from vehicle speed sensor) and fuel flow (signal from ECM).
Fuel flow data is supplied
- from terminal 8 of the ECM
- to combination meter terminal 6.
The vehicle speed sensor sends a voltage signal to the combination meter. The voltage is supplied
- to combination meter terminal 11.
- from vehicle speed sensor terminal 1.

Distance to Empty
The distance to empty (DTE) function calculates the distance that can be travelled on the fuel remaining in the fuel tank, given the current fuel level and current average fuel economy. DTE is displayed in kilometers or miles.